The invention relates to a drive system having an electric direct drive and at least one bearing module, wherein the bearing module has a radial bearing and/or an axial bearing.
Drive systems having electric direct drives are known. In this drive concept, mechanical transmission elements such as, for example, a gear mechanism are dispensed with since the torque is transmitted directly onto the drive shaft by means of a direct drive. A direct drive is therefore, in particular, shaftless since the part to be moved, i.e. the rotor, is provided for connection by flanges to the drive shaft. The torque is generally produced by means of a fixed stator which transmits the torque directly onto the rotor via the air gap.
DE 199 09 307 A1 discloses a production machine with electric drives for use in the plastics industry, with at least one electric drive being embodied as a direct drive.
For a drive system with an electric direct drive it is necessary in many machine applications, in particular wherever increased axial loads affect the direct drive, to correspondingly absorb the axial and radial forces which occur during operation. This is done, for example, by means of axial and radial bearings. However, in the bearing system of a direct drive such standard bearings are often overloaded, and therefore what are referred to as bearing modules are arranged upstream, depending on the load, in order to avoid overloading of the actual bearings. The bearing modules which are embodied with oil lubrication, and also the bearings, heat up during operation owing to frictional and churning losses and even overheat in some cases. As a result, the bearing service lives and the service times of the lubricant are shortened considerably. Furthermore, overheating can also lead to a brief failure of the entire machine.